As a gaming machine of a type of so-called slot machine for playing competitions as to whether or not a combination of symbols forms a winning pattern, for example, there is known a gaming machine in which inner reels and outer reels are combined, symbols of the inner reels are appropriately appeared in windows of the outer reels to thereby change an appearance configuration of the symbols (for example, refer to patent documents 1 and 2). Patent Literature: U.S. Pat. No. 7,473,173B2 and U.S. Pat. No. 5,395,111A.
In the conventional gaming machines, reels are only layered in the same column. For this reason, a player's expectation for winning may not be sufficiently heightened.